My Endo took me off Spiro and Finasteride. She explained to me how it works and told me it was counter-productive. I did notice a little bit of hair thickening, but I get a better result with Biotin. I wish I could remember how she explained it. The purpose of Finasteride is to block T from converting to DHT which is what causes male-pattern baldness.
Anyway, she took me off of those and now I get an injection of Eligard every 90 days, and I take a half-tablet of Casodex daily. The Eligard blocks T production, but the body will convert estradiol to T. The Casodex blocks T receptors so any T conversion will have no effect. In essence, the two have the effect of "chemical castration". Does it work? I have no idea. No symptoms that I can point to, so how does one know, except via lab tests.